Suppose you have an alias on you .bashrc `alias shutdown="sudo shutdown -h now"` and you would like to confirm the execution.

The following script executes any console, alias or gui program with an extra dialog before execution. 

Usage:

tkdialog shutdown

Make sure to 'chmod +x' and put the file into you executables path like /usr/local/bin.

Here is the code:

======
package require Tk
wm withdraw . 
bind . <Escape> {exit}
if {[tk_messageBox -type yesno -icon question\
        -message "Do you really want to $argv?" -parent .] eq "yes"} {
    catch {exec zsh -i -c "$argv"}
}
exit
======

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